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Cepadinium ventriosum
From Fensome et al., 2019:
Cepadinium ventriosum (Alberti, 1959b, p.101, pl.9, figs.14–15) Lentin and Williams, 1989, p.51. Holotype: Alberti, 1959b,
pl.9, fig.14; Eisenack and Klement, 1964, p.239; Fensome et al., 1995, fig.1 — p.1895. Originally Deflandrea,
subsequently Subtilisphaera, thirdly (and now) Cepadinium. Taxonomic junior synonym: Cepadinium variabile,
according to Lister and Batten (1988b, p.43). The nomenclatural type of the genus Cepadinium remains the
holotype of Cepadinium variabile. Age: early Aptian.
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Original description, Alberti, 1959: Deflandrea ventriosa n. sp. (Taf. 9 Fig 14- 15)
Holotype: The specimen preserved in preparation no. We/Al and shown on plate 9, fig. 14.
Locus typicus: Werle 3 borehole (West Mecklenburg)
Stratum typicum: Lower Apt
Diagnosis: Carapace flattened, its outline rounded pentagonal to almost rhombic, lateral edges ± curved outwards. Epi and mortgage almost the same size. Mortgage approximately inversely trapezoidal. With a short ± separated apical horn and usually only a small antapical horn that tapers towards the free end and is at an oblique angle to the long axis of the carapace. Transverse furrow slightly deepened, longitudinal furrow questionable. With a very tight-fitting inner body that fills the entire shell and extends a little into the horns. Shell membrane delicate, inner body membrane finely granulated.
Additions: The large inner body, which extends somewhat into the horns, is characteristic of the species. A trapezoidal loophole under the apex was found in only one specimen. The transverse furrow is wide and shallow. The second antapical horn is usually completely reduced, but occasionally indicated.
Differential diagnosis: Distinguished from all other species of the genus by the outline of the carapace, the extremely large internal body and the very delicate membrane of the carapace.
Dimensions of the holotype: length 67 μ, width 54 μ. In other specimens, the length varies between 65 μ and 78 μ, the width between 51 μ and 57 μ.
Fabric: Over 30 copies.
Occurrence: Unter-Apt of the Werle 3 borehole (West Mecklenburg)
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Cepadinium ventriosum (Alberti, 1959b) Lentin and Williams, 1989, is the taxonomic senior synonym of Cepadinium variabile From the diagnosis for C.variabile of Duxbury (1983). A proximo-cavate cyst possessing well-developed apical and left antapical horns and a right-antapical horn which is reduced to varying degrees. Four body layers are present in the most completely preserved specimens but more commonly only three are observed. In each of these cases, a granular and/or conical body ornament is present on the second layer. A laevorotatory paracingulum is always present, as is a ventral depression which may contain a poorly defined rostrum. The archeopyle is 3A2-4'3I type and the operculum usually remains attached ventrally. No paratabulation other than that reflected by the paracingulum and archeopyle margin has been observed. According to Lister and Batten (1988), this species has a three-layered wall and a combination apical/intercalary archeopyle. Size: length 85-95 µm, width 68-80 µm. Size of C.variabile, overall 46-87 x 42-64 µm.
Cepadinium ventriosum (Alberti, 1959b, p.101, pl.9, figs.14–15) Lentin and Williams, 1989, p.51. Holotype: Alberti, 1959b,
pl.9, fig.14; Eisenack and Klement, 1964, p.239; Fensome et al., 1995, fig.1 — p.1895. Originally Deflandrea,
subsequently Subtilisphaera, thirdly (and now) Cepadinium. Taxonomic junior synonym: Cepadinium variabile,
according to Lister and Batten (1988b, p.43). The nomenclatural type of the genus Cepadinium remains the
holotype of Cepadinium variabile. Age: early Aptian.
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Original description, Alberti, 1959: Deflandrea ventriosa n. sp. (Taf. 9 Fig 14- 15)
Holotype: The specimen preserved in preparation no. We/Al and shown on plate 9, fig. 14.
Locus typicus: Werle 3 borehole (West Mecklenburg)
Stratum typicum: Lower Apt
Diagnosis: Carapace flattened, its outline rounded pentagonal to almost rhombic, lateral edges ± curved outwards. Epi and mortgage almost the same size. Mortgage approximately inversely trapezoidal. With a short ± separated apical horn and usually only a small antapical horn that tapers towards the free end and is at an oblique angle to the long axis of the carapace. Transverse furrow slightly deepened, longitudinal furrow questionable. With a very tight-fitting inner body that fills the entire shell and extends a little into the horns. Shell membrane delicate, inner body membrane finely granulated.
Additions: The large inner body, which extends somewhat into the horns, is characteristic of the species. A trapezoidal loophole under the apex was found in only one specimen. The transverse furrow is wide and shallow. The second antapical horn is usually completely reduced, but occasionally indicated.
Differential diagnosis: Distinguished from all other species of the genus by the outline of the carapace, the extremely large internal body and the very delicate membrane of the carapace.
Dimensions of the holotype: length 67 μ, width 54 μ. In other specimens, the length varies between 65 μ and 78 μ, the width between 51 μ and 57 μ.
Fabric: Over 30 copies.
Occurrence: Unter-Apt of the Werle 3 borehole (West Mecklenburg)
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Cepadinium ventriosum (Alberti, 1959b) Lentin and Williams, 1989, is the taxonomic senior synonym of Cepadinium variabile From the diagnosis for C.variabile of Duxbury (1983). A proximo-cavate cyst possessing well-developed apical and left antapical horns and a right-antapical horn which is reduced to varying degrees. Four body layers are present in the most completely preserved specimens but more commonly only three are observed. In each of these cases, a granular and/or conical body ornament is present on the second layer. A laevorotatory paracingulum is always present, as is a ventral depression which may contain a poorly defined rostrum. The archeopyle is 3A2-4'3I type and the operculum usually remains attached ventrally. No paratabulation other than that reflected by the paracingulum and archeopyle margin has been observed. According to Lister and Batten (1988), this species has a three-layered wall and a combination apical/intercalary archeopyle. Size: length 85-95 µm, width 68-80 µm. Size of C.variabile, overall 46-87 x 42-64 µm.